CVE-2026-98878 Linux CVE debrief

Who should care

Linux kernel developers, system administrators, and users of affected Linux distributions should assess exposure and apply patches or mitigations as needed to prevent potential denial of service and system responsiveness issues. Affected operator, platform, vulnerability-management, and security teams must prioritize patching and review system configurations to ensure system reliability and availability.

Why it matters

The vulnerability in the Linux kernel's irqchip/gic-v5 component can cause denial of service and system responsiveness issues. Linux kernel developers, system administrators, and users of affected Linux distributions should assess exposure and apply patches or mitigations as needed.

• Denial of service due to blocked incoming interrupts
• System responsiveness issues due to delayed priority drops
• Potential impact on system reliability and availability

Technical summary

The Linux kernel's irqchip/gic-v5 component has a vulnerability that causes delayed priority drops after activating interrupts. This can lead to blocked incoming interrupts and significantly affect system responsiveness. The issue arises because, with GICv5, an interrupt of equal or lower priority cannot be signaled until there has been a priority drop via the GIC CDEOI system instruction. The GICv5 driver has moved the priority drop to happen immediately after acknowledging an interrupt in the main GICv5 interrupt handler, rather than as part of irq_eoi(), to resolve this issue. This change helps prevent denial of service and system responsiveness problems.

Defensive priority

Medium

Recommended defensive actions

• Review and apply patches from the Linux kernel maintainers
• Verify system configurations and update to affected versions
• Monitor system responsiveness and interrupt handling
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and source item provide details about the vulnerability, its impact, and affected versions. However, the information is limited, and further verification is required to determine the full scope of the issue.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.